There are a number of components that Thai talk about when they talk about the soul and character.
The soul is divided into two parts: Khwan and Winyan. The khwan is the spirit, the essence of life, or the soul element; while the winyan is the consciousness of the soul. Winyan is from the Pali word vinnana and it refers to the part of the soul which remains after death.
To describe character there are three components: Sanda, Nisai and Chai (Chit-Chai). Sandan is related to the inborn traits that a person has, often dealing with a person’s upbringing. Nisai is used to describe a person’s characteristics or personality. Chai or Chit-Chai can be used interchangably with the term heart or mind. Most often a person’s nisai is described in terms of the character of his chai. Sandan, nisai and chai are frequently used to describe or judge the quality of the character of a person.
Source: Thai Buddhist Character Analysis